This invention relates to a sleeve for use in a mechanical screw press and, more particularly, to an improved sleeve construction for a high-pressure mechanical screw press for continually expressing liquid from liquid contained seeds or grains.
Generally, screw presses are of heavy construction which allows the seed or grain material to be pressed under extremely high pressures and temperatures to express the oils or liquids.
Screw presses generally comprise a main cage having side walls with linear apertures to drain the liquids or oils pressed from the grains or seeds. The side walls of the main cage include linear screen bars supported by semi-cylindrical sleeves wherein pairs of sleeves are fastened together in facing relationship along the length of the main cage to form, in combination with the screen bars, a cylindrical passage. In addition, each sleeve is formed with drainage apertures such that liquid passing through the linear apertures between the screen bars will drain out of the main cage through the sleeve.
Each of the pressure worms includes a screw flight mounted for rotation on a shaft, and pressure collars having a radially outwardly angled circumferential surface are provided between adjacent pressure worms to form restrictions to the passage of material through the main cage of the screw press. Therefore, when the shaft is rotated, thereby rotating the pressure worms, the material within the press is forced into the passage between the pressure collars and the linear screen bars such that the material is compressed in the passage to express out fluids contained in the material. The fluids then pass through the linear apertures defined between the screen bars and through the drainage apertures of the sleeves for collection thereof.
Each of the semi-cylindrical sleeve portions include a plurality of curved circumferentially extending slat portions formed integrally with longitudinally extending runner portions wherein the drainage apertures are defined between the slat portions and the lateral edges of the apertures are defined by the runner portions. Typically each of the slat and runner portions include fluid passages for conveying a cooling fluid through the sleeve to control the temperature of the main cage during an expressing operation.
In order to allow the liquids or oils to drain from the runner portions of the semi-cylindrical sleeve, laterally outwardly from the drainage apertures, the screen bars lying along the runner portions are each provided with laterally extending notches on a face thereof that lies in contact with the sleeve. Thus, fluids passing between the screen bars located on the runner portions will flow through the notches and then pass through the drainage apertures.
The use of the notched out screen bars along the runner portions of the semi-cylindrical sleeves has been found to be inconvenient in that two different types of screen bars are required in the main cage, one being with notches and the other being without notches. In addition, the notches must be aligned with the drainage apertures during installation of the screen bars which increases the amount of time required to install the bars.
Thus, there is a need to provide a means in which a single type of screen bar can be used throughout the main cage and yet allow the liquids or oils expressed from the seeds or grains to pass to the drainage apertures from the screen bars located on the runner portions. Further, there is a need to provide a structure incorporating a screen bar which is uniformly easy to install on the sleeve.